Polyamide fibers and fiber blends of enhanced dyeability

ABSTRACT

A PROCESS FOR INCREASING THE DEEP DYE CHARACTERISTICS OF POLYAMIDES, PARTICULARLY AROMATIC POLYAMIDES WHEN IN COMBINATION WITH KERATINOUS FIBERS AS BLENDS OF NYLON AND WOOL AND THE DYED PRODUCT PRODUCED THEREBY. THE PROCESS INVOLVES PRETREATING THE FIBER IN YARN OR FABRIC FORM WITH A LONG CHAIN ALKYL AROMATIC QUATERNARY AMMONIUM SALT AND SUBSEQUENTLY DYEING THE FIBER WITH AN ACID DYE, THE PRETREATMENT WITH THE QUATERNARY AMMONIUM SALT INCREASES THE AFFINITY FO THE POLYAMIDE FOR ACID DYESTUFFS WITHOUT GREATLY EFFECTING THE DYE AFFINITY OF THE KERATINOUS FIBER, THEREBY PROVIDING GREATLY IMPROVED DYE UNIFORMITY. THE DYE UNIFORMITY IN BLENDS OF BOTH ALIPHATIC AND AROMATIC POLYAMIDES IS INCREASED ACCORDING TO THE PRESENT PROCESS. WHEN THE POLYAMIDE IS AN AROMATIC POLYUAMIDE, IT IS PREFERRED TO USE A CARRIER IN THE DYEBATH TO AID IN THE DYEING OF THE FIBER.

United States Patent C U.S. Cl. 8-21 12 Claims ABSTRACT OF THEDISCLOSURE A process for increasing the deep dye characteristics ofpolyamides, particularly aromatic polyamides when in combination withkeratinous fibers as blends of nylon and wool and the dyed productproduced thereby. The process involves pretreating the fiber in yarn orfabric form with a long chain alkyl aromatic quaternary ammonium saltand subsequently dyeing the fiber with an acid dye. The pretreatmentwith the quaternary ammonium salt increases the afiinity of thepolyamide for acid dyestuffs Without greatly effecting the dye aflinityof the keratinous fiber, thereby providing greatly improved dyeuniformity. The dye uniformity in blends of both aliphatic and aromaticpolyamides is increased according to the present process. When thepolyamide is an aromatic polyamide, it is preferred to use a carrier inthe dyebath to aid in the dyeing of the fiber.

This invention relates to improving the dyeability of certain polyamidesand more specifically aromatic polyamides and also to improving theunion dyeing of keratinous fiber and polyamide fiber blends.

Aromatic polyamide fibers have recently been introduced to the textileindustry. In general, the aromatic polyamide to which reference is madeis a polymeric structure wherein an aromatic ring is introduced ineither diamine or dibasic acid with the other monomer containing thealiphatic carbon chain component. When an aromatic diamine is employed,it is preferred that the amine groups be displaced from the aromaticring by at least one carbon to prevent objectionable color formation.When an aromatic dibasic acid is employed, the placement of the carbonylgroups should be such that a stiff polymer will not result as aconsequence of resonance. Representative of the preferred types ofaromatic polyamides are polymetaxylylene adipamide, andpolyhexamethylene terephthalamide:

0 o I n n THN-CHz-CHz-CHz-CHz-CHz-CHz-NHC-OCJ attempting to obtain aunion dye in blends of aromatic polyamides and keratinous fibers, it is,therefore, not only necessary to increase the buildup of acid dyestuffson the aromatic polyamide fiber but also to inhibit the buildup of aciddyestuffs on the keratinous fiber in order that the bath will not beexhausted prior to the aromatic polyamide being dyed.

Union dyeing of Wool-polyamide blends and especially wool-nylon blendsis well known in the art. When dyeing mixtures of wool and nylon,however, a difficulty may arise especially with polysulfonated dyesowing to the low saturation value of nylon which contains basic groupsonly at the ends of the long chains. Hence, nylon quickly becomessaturated with dye except in the case of pale shades and when using amixture of dyes this may result in one component being excludedaltogether. With equalizing acid dyes, the nylon portion usually dyesdarker than the Wool in pale shades and conversely with heavy shades.Equalizing acid dyes are commonly used for the preparation of paleshades by adding small quantities of colorless compounds possessing highaffinity for nylon to the dyebath. These colorless compounds beingcompounds such as, for instance, Calsolene oil HS (leveling agentmarketed by Imperial Chemical Industries) or Perminal BX (leveling agentmarketed by Imperial Chemical Industries). These leveling agents act asa restraining agent for the nylon and thereby produced a solid shade inthe wool-nylon blend. Where, however, dark shades are desired,equalizing acid dyes are usually replaced by neutral dyeing acid dyeswhich build up well on nylon in that these dyes contain the minimumnumber of sulfonic groups. While techniques such as the aforementionedtechnique are available for producing dark shades, wool dyers prefer,where possible, to use equalizing acid dyes because of the brightnessand ease of application of this category of dyestuffs.

The most common form of union dyeing is one in which the componentfibers require completely different but not compatible dyes, thus.enabling each fiber to be dyed without interference from the other. Thisideal sitnation, however, is not often achieved. In most cases, onefiber is dyed while the other fiber is stained. As a result of thisstaining, the fabric must be scoured prior to being subjected to asecond dyeing operation. Should the second dyeing operation stain thepreviously dyed fiber, still another scouring operation is required toremove this staining effect. It is readily apparent that in uniondyeing, a single dyebath employing a single dyestuff is preferred to aprocess employing a plurality of dyebaths and a plurality of scouringoperations.

It is, therefore, an object of this invention to provide a process forimproving the dyeability of aromatic polyamides.

It is a further object of this invention to provide a deep dyed aromaticpolyamide fiber.

It is an additional object of this invention to provide an improvedunion dyeing process for keratinous fiber, polyamide fiber blend.

It is another object of this invention to provide a keratinous fiber,polyamide fiber blend textile product union dyed with a single dyestuff.

It is still another object of this invention to provide a dark shadeunion dyeing process employing a single equalizing acid dye forkeratinous fiber, polyamide fiber blends.

In accordance with this invention, it has now been discovered that inunion dyeing operations on keratinous fiber, polyamide fiber blendswherein the dyeability of the polyamide component must be enhanced whilethe dyeability of the keratinous fiber component must be inhibited, adyebath employing a single equalizing acid dye may be employed bypretreating the keratinous fiber, polyamide fiber blend, with aquaternary ammonium salt having the following general formula:

wherein R is a long chain alkyl group having a chain length of from C toC R and R are short chain alkyl groups independently selected fromcarbon chains of from C to C and X is a member selected from the groupconsisting of chloride, fluoride, bromide, sulfate and hydroxide.Preferably, R and R" are CH groups and X is a chloride. It is preferredthat the dyebath also contain a carrier such as, for instance, Carolid(sodium salt of ortho phenyl phenol marketed by Tanatex Co.).Apparently, the carrier serves to promote the entry of dyestuffs intothose new dyesites which have been provided by the presence of thequaternary ammonium salt. While the quaternary ammonium salt is suitablefor obtaining improved dyeings of any polyamide, the process of theinvention is especially suited for use with aromatic polyamide fibers,either alone or in the form of blends with keratinous fibers. Thequaternary ammonium salt pretreatment of aromatic polyamides is found toproduce products which are dyed to darker shades and to a deeper degreeof penetration.

When the keratinous fiber, polyamide fiber blend being union dyedcontains aromatic polyamide, the dyestuff employed may be of any shade.Where, however, the keratinous fiber polyamide fiber blend being uniondyed contains aliphatic polyamide, preferred union dyeing results areobtained with dark shades of equalizing acid dyes. It is also found thatwith aliphatic polyamide blends, the presence of a carrier is notnecessary.

When aromatic polyamide fibers in unblended form are being dyed forpurposes of obtaining darker shades, it is preferred that a carrier bepresent and that the dyestuff be a monosulfonated acid dye. Themonosulfonated acid dyes are found to give good penetration, lightfastness and color build-up, and to have good resistance to sublimationand crocking. The following dyestuffs have been found to be especiallysuitable for use with unblended aromatic polyamide fibers pretreatedwith a quaternary amine salt: Dimacide Red 2B; Nylanthrene Yellow FLW;Nylanthrene Orange SLF; Supernylite Yellow 3G; Nylomine Red 2B3 (C.I.Acid Red 266); Nylomine Brown B; Nylomine Scarlet B; Nylomine Orange GS(C.I. Acid Yellow 64); Nylomine Blue GS (C.I. Acid Blue 14); DimacideBlue J S; Cibalan Yellow F-GL (C.I. Acid Yel- W 128) Irgalan Grey BL(C.I. Acid Black 58); Cibalan Red 2GL (Cl. Acid Red 211).

It should be understood that the term keratinous fiber as employedherein is meant to include any of the fibers containing major quantitiesof any of the various sulfur-containing fibrous proteins such as, forinstance, wool, vicuna, llama, alpaca, cashmere, angora, camel hair,regenerated keratin and the like.

The term polyamide as employed herein is meant to include any polymericmaterial containing the characteristic amide type component whetheraliphatic or aromatic such as, for instance, polyhexamethyleneadiparnide, polymetaxylylene adipamide, polyhexamethyleneterephthalamide and the like.

The term carrier as employed herein is meant to include any organiccompound which loosens the tight bonding between the long fibermolecules thus facilitating entry of dye molecules. Specific carrierswhich may be deemed to be included in this category are phenols,aromatic esters, chlorinated aromatic hydrocarbons and the like. Thepreferred carrier of this invention is ortho phenyl phenol which isintroduced into a dyebath in the form of a sodium salt.

In general, it is preferred that the pretreatment be such as to resultin a pickup of .1 percent by weight to about 5 percent by weight ofquaternary ammonium salt based on the dry weight of the fabric, the mostpreferred amount being about 2 percent by weight. When a carrier isincluded in the dyebath, it is preferred that the carrier be present inamounts of from about .1 percent by weight to about 20 percent by weightand most preferably about 5 percent by weight.

The following specific examples are given for purposes of illustrationand should not be considered as limiting the spirit or scope of thisinvention.

EXAMPLE 1 A polyhexamethylene terephthalamide yarn is treated in a bathcontaining 2% by weight of dimethyl benzyl (myristyl-cetyl) ammoniumbromide plus 5 grams per liter of Carolid (sodium salt of ortho phenylphenol marketed by Tanatex Co.), the bath being maintained at about 98C. The yarn is then washed and placed in a dyebath for about threeminutes at a temperature of about 170 F., the bath containing 6.5 gramsper liter of solvent FT (a polyethoxyether of a fatty alcohol in a lowboiling solvent) (carrier marketed by Francaise des Matieres Coloromtes,S.A., France), 2% by Weight of Eric Fast Scarlet B (CI. No. 14710)maintained at a pH of about 4. The same procedure is repeated with asample of polyhexamethylene terephthalamide yam which is not given thepretreatment with dimethyl benzyl (myristyl-cetyl) ammonium chloride.The yarn which has been pretreated with the quaternary amine is found todye a much darker shade and to a deeper degree of penetration than thesample which was not pretreated.

EXAMPLE 2 A challis fabric prepared from polymetaxylylene adipamide yarnis placed in an aqueous bath maintained at C. containing 2% by weightBTC 824 fatty alkyl dimethylbenzyl ammonium chloride (quaternaryammonium salt marketed by Onyx Chemical Corp.) for a period of about 15minutes. The fabric is then rinsed and placed in an aqueous bathmaintained at 50 C. and containing 3% Tinegal NA condensation product ofethyleneoxide with a fatty alcohol (surfactant marketed by Geigy Chem.-ical C0.) and 2% CH COOH. After a mild agitation 2% by weight ofNylomine Orange GS added and the bath agitated for two minutes and thenraised to the boil, 1% of H 50, is added and the bath boiled for anadditional 50 minutes. The dyed fabric is then given a cold rinse andcured at 385 F. for 3 minutes. The dyeing procedure is repeated on anidentical challis fabric which has not been given the quaternaryammonium salt pretreatment. The quaternary ammonium salt treated fabricis found to dye a much darker shade and to deeper degree of penetrationthan the untreated sample.

EXAMPLE 3 A tropical fabric composed of 55 percent by Weightpolyhexamethylene terephthalarnide and 45 percent by weight wool isscoured with a nonionic detergent. The fabric is pretreated in a bathmaintained at about 98 C. with a 10 percent solution of a quaternaryammonium salt having the following formula:

The fabric is then washed and placed in a dyebath for about threeminutes at a temperature of about F., the bath being composed of 2percent by weight Nylomine Blue GS, 3 percent by weight Penigal NA, 3percent by weight ammonium acetate and 2 percent by weight acetic acid.The dyed fabric is then scoured in a common scour bath. A uniform colorbuild-up on both the Wool and the aromatic polyamide components is foundto take place.

The procedure is again repeated with the exception that the pretreatmentwith the quaternary ammonium salt is omitted. The resultant fabric isfound to be deeply dyed on the wool component and only lightly dyed onthe aromatic polyamide component.

EXAMPLE 4 A knit stocking fabric composed of 50 percent nylon 6,6 and 50percent wool is scoured in a nonionic detergent. The fabric ispretreated in a bath maintained at about 98 C., the bath being a percentaqueous solution of a quaternary ammonium salt having the following Thefabric is then washed and placed in a dyebath for about three minutes ata temperature of about 170 F., the bath being composed of 3 percent byweight Polar Brilliant Blue RAW (C.I. Acid Blue 80), the bath beingadjusted to a pH of about 5 by the addition of sufficient acetic acid.The dyed fabric is then scoured in a common scour bath. A uniform colorbuild-up on both the wool and nylon 6,6 components is found to takeplace.

The procedure is again repeated with the exception that the pretreatmentwith the quaternary ammonium salt is omitted. The resultant fabric isfound to be deeply dyed on the wool component and only lightly dyed onthe nylon component.

Having thus disclosed the invention, what is claimed 1. A process forunion dyeing a keratinous fiber polyamide fiber blended textile materialwith a single dyestuif, said process comprising pretreating said textilematerial with a quaternary ammonium salt having the following generalformula:

wherein R is a long chain alkyl group having a chain length of from C toC R and R are short chain alkyl groups independently selected fromcarbon chains of from C to C and X is a member selected from the groupconsisting of chloride, fluoride, bromide and sulfate, contacting saidtextile material with a hot aqueons acidic dyebath containing an aciddye, dyeing said material and subsequently rinsing said dyed materialthereby obtaining a dyed material of improved uniformity.

2. The dyed textile product produced by the process of claim 1.

3. The process of claim 1 wherein the keratinous fiber is wool.

4. The process of claim 1 wherein the quaternary ammonium salt isdimethyl benzyl (myristybcetyl) ammonium chloride.

5. The process of claim 1 wherein the dyestuff is a monosulfonated aciddye.

6. The process of claim 1 wherein a dye carrier is used in the dyebath.

7. The process of claim 1 wherein the quaternary ammonium salt is addedto the fiber in an amount of 0.1 to 5 weight percent.

8. The process of claim 1 wherein R and R" are both CH groups and X ischloride.

9. The process of claim 1 wherein said polyamide is an aromaticpolyamide and wherein said single dyestuff is applied in the presence ofa carrier.

10. The process of claim 1 wherein said polyamide is an aliphaticpolyamide and wherein said dyestuff is a dark shade dyestuif.

11. The process of claim 1 wherein R and R are both CH groups and X ischloride and wherein said polyamide is polyhexamethylene terephthalamideand said dyestuff is applied in the presence of a carrier.

12. The process of claim 1 wherein said aromatic polyamide fiber is afiber selected from the group consisting of polymetaxylylene adipamideand polyhexamethylene terephthalamide.

References Cited UNITED STATES PATENTS 2,371,536 3/1945 MacGregor 8-213,380,969 4/1968 Hill et al 8-55 3,338,660 8/1967 Biedermann 821 OTHERREFERENCES H. C. Speel: Textile Chemicals and Auxiliaries, Reinhold Pub.Co., 1952, pp. 334, 335, 350, 351, 359, 360.

NORMAN G. TORCHIN, Primary Examiner J. E. CALLAGHAN, Assistant ExaminerUS. Cl. X.R. 884, I72, 178

